This invention relates to a vehicular airbag restraint device, and more particularly to such a device having a compartmentalized airbag knee bolster which increases the pressure on areas of contact with the knees of a vehicle's occupant, thereby restraining forward motion of the knees.
When a vehicle is involved in a frontal crash, the occupants in the front seat are driven forward. To prevent the occupants from submarining under or sliding into the instrument panel, their knees must be restrained from forward translation. This may be accomplished by placing a knee bolster in front of the position the knees will be in prior to their forward translation. However, reactive type knee bolsters which function on the principal of a single compartment airbag have the disadvantage that on impact of the knees with the airbag, the airbag loses rigidity in the impact area. This is due to gas flowing from the impact area of the bag to other areas within the airbag. Accordingly, the effectiveness of the airbag is reduced due to low rigidity of the airbag in the impact area.